Studies on new antifungal antibiotics, guanidylfungins A and B. II. Structure elucidation and biosynthesis

The structures of guanidylfungins A and B were elucidated from the physico-chemical properties of these compounds and the structures of the degradation products by ozonolysis and periodate oxidation. The guanidylfungins consist of a 36-membered polyhydroxyl lactone ring, a guanidine and a monoester of malonic acid. The labelling experiments with sodium [1-13C]acetate and sodium [1-13C]propionate revealed that twelve units of acetate and nine of propionate were incorporated into the molecule of guanidylfungin A.